Format

Send to

Choose Destination
See comment in PubMed Commons below
Hum Mutat. 2009 Nov;30(11):1551-7. doi: 10.1002/humu.21108.

Clinically reported heterozygous mutations in the PINK1 kinase domain exert a gene dosage effect.

Author information

1
Department of Neurology, Singapore General Hospital, Singapore. gnrtek@sgh.com.sg

Abstract

Mutations in the gene encoding phosphatase and tensin homolog (PTEN)-induced kinase 1 (PINK1) have been associated with the loss of dopaminergic neurons characteristic of familial and sporadic Parkinson disease. We developed an in vitro system of stable human dopaminergic neuronal cell lines coexpressing an equivalent copy of normal and mutant PINK1 to simulate "heterozygous" and "homozygous" states in patients. Mutants in the N-terminus, C-terminus, and kinase domain were generated and cloned into a two-gene mammalian expression vector to generate stable mammalian expression cell lines producing an equivalent copy number of wild-type/mutant PINK1. The cell lines were subjected to oxidative stress and the rate of apoptosis and change in mitochondrial membrane potential (DeltaPsi(m)) were assessed. Cell lines expressing kinase and C-terminus mutants exhibited a greater rate of apoptosis and decrease in DeltaPsi(m), and increased time-dependent cell loss when subjected to oxidative stress compared to the wild-type. Cell lines expressing two copies of kinase mutants exhibited a greater apoptosis rate and DeltaPsi(m) decrease than those expressing one copy of the mutant. In time-dependent experiments, there was a significant difference between "homozygous," "heterozygous," and wild-type cell lines, with decreasing cell survival in cell lines expressing mutant copies of PINK1 compared to the wild-type. We provided the first experimental evidence that clinically reported PINK1 heterozygous mutations exert a gene dosage effect, suggesting that haploinsufficiency of PINK1 is the most likely mechanism that increased the susceptibility to dopaminergic cellular loss.

PMID:
19847793
DOI:
10.1002/humu.21108
[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Wiley
    Loading ...
    Support Center